Gas cylinders are widely used in medical and industrial settings for the dispensing of gases and mixtures of gases such as oxygen, nitrogen, helium, nitrous oxide, heliox, etc. While often cylinders included a visible means to indicate current cylinder contents with either mechanical or electronic manometers, the information is not transmitted to users as it relates to the current usage situation and often requires further processing of the information by the user to produce useful information. In the medical setting, the determination of time remaining relative to the current use rate of the gas cylinder is performed from tables and charts that are not always readily accessible leading to the non-continuous monitoring of patients and reduced patient safety. In industrial settings, cylinders are often used to provide calibration gases for critical process equipment where calibrations take extended periods of time with operators often stepping away to conduct other activities. An objective of the present invention is to alleviate some or all of the challenges in linking the use state of gas cylinders to the relevant information the user requires from the cylinder.